וְאָר֣וּר נוֹכֵ֗ל וְיֵ֤שׁ בְּעֶדְרוֹ֙ זָכָ֔ר וְנֹדֵ֛ר וְזֹבֵ֥חַ מָשְׁחָ֖ת לַֽאדֹנָ֑י כִּי֩ מֶ֨לֶךְ גָּד֜וֹל אָ֗נִי אָמַר֙ יְהוָ֣ה צְבָא֔וֹת וּשְׁמִ֖י נוֹרָ֥א בַגּוֹיִֽם׃
Ma maledetto sia colui che tratta con astuzia, mentre ha un maschio nel suo gregge, e giura e sacrifica al Signore una cosa imperfetta; Poiché io sono un grande re, dice l'Eterno degli eserciti, e il mio nome è temuto tra le nazioni.
Mesilat Yesharim
It is further written: "But cursed be the deceiver who has in his flock a male, yet he vows and sacrifices to the L-rd a blemished one. For I am a great King [says the L-rd of Hosts]" (Malachi 1:14).
Mesilat Yesharim
To illustrate, obviously, it is proper for every person to arrive early and run to perform a mitzva, striving to be among those occupied in it. However, sometimes this could lead to a dispute, whereby there will be more desecration of the Name of Heaven and shame to the mitzva than honor. In such cases, certainly the Chasid is obligated to abandon the mitzva and not pursue it.
Mesilat Yesharim
The general principle: whatever is essential in the mitzva, should be done before all mockers. But whatever is not essential and causes laughter and ridicule, one should not do.